Hydraulically actuated orienting device



July 2, 1963 'r. M. FRISBY HYDRAULICALLY ACTUATED ORIENTING DEVICE Filed D60. 2, 1960 INVEN THOMAS M FRISB A TTORNE Y 3,095,924 HYDRAULICALLY ACTUATED ORIENTING DEVICE Thomas M. Frisby, Denver, Colo, assignor to Eastman Oil Well Survey Company, Denver, Colo., a corporation of Delaware Filed Dec. 2, 1960, Ser. No. 73,348 3 Claims. (Cl. 166-4) This invention relates to a device employed in earth boring for determining and establishing orientation of deflecting tools with respect to the low side of the bore, and more particularly relates to an orienting device which is operative under the influence of fluid pressure to enable surface indication of orientation of a deflecting tool, for example, to carry on directional well drilling operations.

A common problem associated with the drilling of subsurface wells is that of proper orientation of the drill string for continued drilling in the desired direction, especially to accomplish this by remote control at the surface and in such a way that there is a reliable and accurate indication of proper alignment or orientation of the drill tool. Accordingly, it is a primary object of the present invention to make provision for an orienting device by which proper orientation of the drill tool may be accomplished by remote control at the surface together with a positive surface indication of proper orientation; and, whereby the moving parts comprising the orienting device, although being dependent upon pressure conditions in the well, will in no way be distorted in mechanical operation by the pressure conditions.

It is another object of the present invention to provide for an orienting device incorporating a minimum number of moving parts which is capable of providing an accurate surface indication of orientation of drill tools and where the parts employed to establish proper alignment of the drill tools are completely isolated from the effects of the well and drill fluid pressure.

It is a further object to make provision for a positiveacting, reliable orienting device which is automatically operative either to determine orientation or to establish proper orientation of deflection tools in the well for continued drilling in the desired direction.

It is an additional object of the present invention to make provision for an improved way of aligning a deflection tool in a well bore to insure free relative movement between the parts and in such a way a to overcome the distorting effects of well and drilling fluid pressure, and yet, to employ the fluid pressure as an accurate indication of orientation of the device within the well bore.

In accordance with the present invention, the orienting device is preferably designed for connection to the drill string just above the deflecting tool or similar element. Essentially the device is defined by an outer cylindrical section having an inwardly disposed race, and a generally tubular piston is disposed for limited sliding movement in said cylindrical section with an exterior shoulder providing an orienting notch therein. A rolling member, such as, a ball is movable along the race toward the low side thereof when the device is inclined in the well bore and normally will maintain the shoulder and race in spaced relation, until it becomes aligned with the notch portion which occurs when the device is rotated to align the notch with the low side and the ball. Then, the piston is movable longitudinally in relation to the sub and, by delivering fluid under pressure through said piston, a valve means associated with the piston is made responsive to mi tas Patent longitudinal movement of the piston to permit a reduction 7 in pressure of the fluid so as to signal the alignment of the notch portion with the ball on the low side of the device. In this relation, an accurate surface indication of orientation of the device is made possible; and, by predisposing the tool with respect to the notch on the device the facing of the tool is indicated by the pressure reduction.

The above and other objects and advantages of the present invention will become more readily understood from the following detailed description taken together with the accompanying drawings, in which:

FIGURE 1 is a detailed vertical section view of a preferred embodiment of the orienting device, and illustrating the relative disposition between the parts prior to orientation.

FIGURE 2 is a fragmentary section view illustrating the relative disposition between the parts after orientation has taken place; and

FIGURE 3 is a section view taken on line 33 of FIGURE 1.

Referring more particularly to the drawings, there is shown by way of illustration a preferred embodiment of the present invention in the form of an orienting device 10 wherein the parts comprising the structure are contained within a suitable sub 12. The sub 12 is merely representative of various forms of generally cylindrical sections which may be employed for interconnection in a drill string and accordingly at one end the sub may be internally threaded as at 13, for example, for connection to the lower end of a drill pipe section and may further include a lower threaded stem end 14 for connection with a deflecting tool, also not shown. It will be evident, though, that other than to serve as a housing for the vari ous parts forming the device of the present invention the particular form of construction of the sub or cylindrical section itself is of no importance and may be connected in various ways and at any desired location in the drill string, keeping in mind that its primary function will be to serve as a way of orienting the deflecting tool to resume drilling in the desired direction.

A central, continuous passage generally indicated at 16 extends through the sub for disposition of the various elements comprising the orienting device, and these elements are comprised broadly of upper seal ring 17, lower seal ring 18, a slidable piston assembly 20 and free-floating pistons 21 which are positioned in lateral bores 22 communicating with race 31 just beneath the upper seal ring 17. In addition, a compression spring 24 is shown positioned at the lower end of the piston assembly lit and a rolling member in the form of a ball 25' is shown positioned on the top surface of the lower seal ring 18.

The seal rings 17 and 18 serve generally to form a complete seal between the inner wall of the sub 12 and exterior of the piston assembly 24) so that in a manner to be described drilling fluid forced under pressure through the sub will be constrained to pass completely through the interior of the piston assembly and will not leak around the exterior thereof. Accordingly, the upper seal ring may include .a circumferential groove 27 to receive diametrically-opposed set screws 28 which extend laterally through the wall of the sub and in this way to hold the upper seal ring 17 securely in place at the top of the main passage 16. Additionally, an O-ring seal 29 is positioned in a groove toward the lower end of the seal ring; also, interposed between the exterior of the piston assembly and inner surface of the seal ring 17 is an enlarged flexible seal 30' held in place by a snap ring 23. The lower seal ring 18 is made'relatively long compared to the upper seal ring 17 for the reason that it serves other purposes than merely as a seal between the sub and the piston assembly. For example, the top surface 31 of the seal ring 18 is made perfectly level and smooth so as to define essentially within the confined space between the piston assembly and inner wall of the sub 2. race or ball support surface for the rolling member 25.

In this way, the ball 25 will be highly sensitive -to even slight inclinations of the orienting device as a whole so as to tend to roll toward the lower side of the race 31. Positioned just beneath the top surface 31 are oppositelydirected grooves for reception of O-rings 32 and 33 engaging respectively the inner surface of the sub and the outer surface of the piston assembly. Just beneath the double seal portions is another circumferential groove 37 again to receive atone side thereof a lower set screw 34 projecting laterally through the wall of the bore. The lower portion of the seal ring 18 also includes a lateral bore 35 to receive set screw 36 which projects therethrough into engagement with the piston assembly for a purpose to be described. The lower extremity of the seal ring 18 is formed to provide a relatively wide and deep annular opening 38 adjacent the exterior of the piston assembly. Along with the lower screw '34 it may be desirable to provide a ledge 39 in the wall of the passage 16 to serve as the main support for the seal ring 18 Within the sub, the seal ring including a corresponding shoulder portion 40 which rests against the ledge 39.

The piston assembly 20 is generally tubular in configuration and cooperates in a unique way with the other elements of the orienting device in carrying out the principles of the present invention. Adjacent the upper end of the piston assembly is an external shoulder 42 which serves as a base for the flexible seal 30. In spaced relation below the shoulder 42 is a relatively thick external shoulder 44 which extends outwardly in annular fashion just beneath the seal ring 17 and into contiguous relation with the inner surface of the sub 12 opposite the lateral bores 22. It will be noted that the external shoulder 44 actually extends in spaced relation above the race 31 so as to form a completely confined area for movement of the ball 25 between the bottom surface of the shoulder 44 and top surface 31 of the lower ring 18. Additionally, the external shoulder 44 includes a downwardlyfacing notch or recess 45 which is of a size, when aligned, to receive the ball or rolling member -25 therein and actually to permit the piston assembly to slide downwardly until the bottom surface of :the shoulder 44 comes into contact with the race surface 31, as best seen from FIGURE 2.

In order to receive the inner extremity of the set screw 36 positioned in the lower seal ring 18, a longitudinal slot 47 is formed in the wall of the piston assembly and in this manner, the piston assembly is restrained from rotating relative to the lower seal ring 18 but is free to slide longitudinally in relation to the ring 18 since the set screw is free to move through the slot 47. There is also spaced around the wall of the piston assembly a number of ports or openings 48 and for example a pair of openings may be formed in diametrically opposed relation at the lower end of the assembly. In order to normally seal and close off the area between the lower seal ring 18 and lower end of the piston assembly, a flexible annula-r seal 50 is positioned on the piston assembly for disposition within the annular opening 38, the seal being held in place by means of snap rings 51. Positioned beneath the seal 50 is a sleeve 52 having an enlarged lower end portion 53 which acts as the upper limiting member for the compression spring 24, the lower end of the compression spring abutting against i-nturned shoulder 54 of sub 12 so as to effectively bias the entire piston assembly in an upward direction towards the position shown in FIGURE 1.

At the lower extremity of the piston assembly 20 is an orifice or flow nozzle 56 seated between an internal shoulder of'the piston member 76 and a snap ring 77 as shown, and the size of the opening formed by the orifice preferably conforms to the size of the ports 48. Prior to orientation of the sub and deflecting tool the orifice serves along with the interior of the piston assembly as the sole passage for flow of fluid under pressure through the sub and accordingly the reduction in pressure caused tion of the scribe line 71.

as the fluid passes through the orifice creates a differential pressure tending to urge the piston assembly downwardly against the bias of the spring.

The confined space formed between the shoulder 44 and race'31 for movement of the ball is preferably filled with fluid to damp the action of the ball and also to allow for pressure equalization between the confined space and the hydrostatic head in the well bore itself. In this way, the pressure developed by the fluid in the confined space will prevent the shoulder 44 normally from moving downwardly against the top surface of the ball 25 and preventing its free-rolling movement around the race 31 when the piston assembly is under pressure. Moreover, it is desirable to maintain a substantially constant pressure equalization between the space and that in the well boreno-twithstandi-ng changes in volume which take place when the piston assembly travels downwardly, for example to the position shown in FIGURE 2, or to compensate for temperature changes. To this end, the floating pistons 21 are positioned in the lateral bores 22 as mentioned and serve as the principal means of equalization of the pressure between the space in the race 31 and that in the well bore. In order to seat the floating pistons within the lateral bores 22 each bore is provided with an outer sleeve 69 secured within the bore and a. generally circular piston member 21 is positioned in the sleeve for free sliding movement therealong in response to differences in pressure on opposing sides. The piston member 21 is generally in the form of a circular plug 61 having a circular seal 63 positioned on its circumference to engage the inner wall of the sleeve and with a tapered threaded opening 64 formed in the center of the plug to receive a correspondinglyshaped core 65. For removal of the plug 61, it is only necessary to remove the core 65 and to substitute a tool having a similarly formed threaded end for engagement with the opening 64. Additionally, in order to limit the outward movement of the plug 61 for example when a high internal pressure is developed in the confined space, a snap ring 67 is positioned adjacent the outer end of the sleeve 60. In filling the cavity, any suitable motor oil, such as an SAE 10-20 all-Weather motor oil may be employed. The cavity may be filled by first inserting a floating piston in one lateral bore then laying the sub on its side with the open bore up and depositing the oil in the confined space through the open bore. The inserted piston then may be reciprocated manually within the sleeve to work the air gradually out of theupper part of the confined space in order to permit complete filling of the confined area, followed by insertion of the second piston.

Before connecting the orienting device into the drill string, it is desirable to align the notch or recess 45 in a position such that when the notch moves into alignment with the ball on the low side of the hole, the whipstock or other deflecting tool will be facing in the desired direction. Through this expedient, there is eliminated the necessity for additional rotation of the drill string after orientation has been established. Since the orienting notch 45 is effectively hidden within the sub upon installation, a special notch 70 may be formed in the top of the piston assembly and this may be aligned with a facing line 71 scribed on the surface of the sub at or diametrically opposed to the desired disposition of the orienting notch. Once properly aligned, it being understood that the notch is aligned 180 or on the opposite side to the scribe line, the seal ring 18 may then be evenly secured in place by tightening the set screw 34. The inner set screw 36, as stated, serves to retain the piston assembly against rotation relative to the seal ring 18 and in turn the seal ring 18 is securely held in place by the set screw 34.

Once aligned, the entire assembly may be made up with the deflecting tool connected so that it faces in the direc- The entire drill string assembly may then be lowered to the bottom of the hole in a conventional manner following which pumps at the wellsurface may be started and operated for a few minutes at a speed and volume that can be repeated at each step of the orientation. Pressure at this initial volume may then be checked and recorded. At this point, the pump may be shut down and the drill string rotated or 210 degrees and worked up and down several times to work out the torque, As. the pipe is rotated and, assuming that there will be at least some slight inclination of the sub and connected deflecting tool away from vertical, the ball 25 will be gravity responsive to seek and remain at the low side of, thehole. The pumps may then be operated between each rotative step at. the same volume, and the pressure again noted and recorded. These steps may be repeated until a drop in pump pressure is noted which will indicate that the notch 45 in the piston assembly is in line with the ball at the low side. The reason for this is best seen from FIGURE 2 Where it will be noted once the piston is free to move downwardly relative to the seal rings and sub assembly, the lower seal 50 will move downwardly a corresponding distance to clear the opening 38 while at the same time ports 48 similarly move downward a suflicient distance to communicate with the opening and with the outside passage 16 formed in the sub assembly. Since, as described, the ports 43 are of a size generally corresponding to the size of the orifice 56, when the ports do move into alignment with the opening 38 a considerable reduction in pressure will ensue as is made apparent from the considerable increase in area through which the fluid may flow. Furthermore, by providing the limited opening formed by the orifice 56- it will have the effect of creating a differential pressure between the top and bottom of the piston assembly urging the assembly downwardly against the force of the spring 24 so that the orienting notch 45 if properly aligned with the ball will immediately permit the shoulder and entire piston assembly to move to its lower limit.

To align the notch, it will be noted that the pumps must be shut down when the pipe or drill string is being rotated so as to eliminate the differential pressure between the top and bottom of the piston assembly thereby permitting the piston assembly to be urged upwardly in response to the bias of the spring 24 so that the ball will be free to roll along the race 31 to the low side of the hole. In addition, by maintaining pressure equalized conditions within the confined space for the ball and passage 16, the piston assembly is made responsive solely to the urging of the spring and the pressure of the drilling fluid and thus may be closely regulated in orienting the deflecting tool.

Once initial orientation has been established, it can easily be checked by moving 20 or 25 degrees on either side of the low pressure point, checking pump pressure at these positions and then returning to the point where orientation was first made. Assuming for example that a whipstock is being employed, once orientation has been established the whipstock may be set down to shear its pin following which drilling may proceed in a conventional manner.

By isolating the orienting parts, and especially the rolling member, greatly increased reliability and accuracy in operation is attained since the flow of fluid through the interior of the orienting device will have no elfect whatsoever upon movement of the parts and again particularly the rolling member. Of course, the pressure of the drilling fluid may be utilized effectively to establish at desired intervals a diiferential pressure causing the piston assemebly to move downwardly, but other than this, the drilling fluid will not influence the operation of the aligning elements of the device. It will further be evident that the annular opening 38, ports 48 and seal 50 efiectively form a valve assembly which is normally closed when the piston assembly is in the up position and which is responsive to downward movement of the piston assembly, once alignment of the notch and ball have been established, to open to substantially increase the flow area through the assembly as a surface indication that orientation has been established. Accordingly, various types of valve means may be employed which are responsive to relative longitudinal movement between the piston assembly and seal ring to act as a signaling means at the surface to rel-ate that the tool is properly oriented.

Frorn the foregoing, it will be understood that a number of changes and modifications may be made in the construction and arrangement of parts comprising the orienting device of the present invention without departing from the scope thereof, as defined by the appended claims and reasonable equivalents thereof.

What is claimed is:

'1. An orienting sub for insertion in a drill string for earth boring operations comprising: an outer tubular member having a bore therethrough; a tubular piston in said bore axially and radially movable therein and having at least one orifice in its wall near its lower end, an external annular shoulder having a downwardly facing notch therein, and a restricted opening at its lower end defining a first outlet passage constituting an outlet area for the passage of drilling fluid from said sub; the hollow of said piston forming a passageway for drilling fluid through said sub; a tubular seal between said piston and said bore located below said external shoulder and having an internally recessed portion at its lower end to form an annular recess between its lower internal surface and said piston, the upper end of said seal and the lower surface of said external shoulder defining an annular race; means for indicating the orientation of said piston and said notch radially with respect to said outer tubular member; means for securing said piston in oriented position against radial movement; means for equalizing pressure between said race and the hydrostatic head of the well bore; a second outlet passage from said passageway defined by said orifices and said annular recess; sealing means carried by said piston sealing said second outlet passage when the piston is in its upper position and opening said second outlet pas-sage when the piston is moved to its lower position; spring biasing means between the bottom of said piston and said bore biasing said piston upwardly against the inlet pressure of drilling fluid in said pass-ageway; and a ball in said race holding said piston in its upper position when the ball is not in said notch; whereby, when said ball is in said notch the piston will move to its lower position to open said second outlet passage to thereby increase said outlet area from said passageway resulting in a noticeable decrease in drilling fluid pres sure in said passageway to indicate that the ball is in said notch.

2. The sub of claim 1 in which said pressure equalizing means comprises at least one reciprocating piston mounted in a transverse bore in said outer tubular member in communication with said race.

3. An orienting sub for insertion in a drill string for earth boring operations comprising: an outer tubular member having a bore therethrough; a tubular piston in said bore axially and radially movable therein and having at least one orifice in its wall near its lower end, an external annular shoulder having a downwardly facing notch therein, and a restricted opening at its lower end defining a first outlet passage constituting an outlet area for the passage of drilling fluid from said sub; the hollow of said piston forming a passageway for drilling fluid through said sub; a tubular seal between said piston and said bore located below said external shoulder and having an internally recessed portion at its lower end to form an annular recess between its lower internal surface and said piston, the upper end of said seal and the lower surface of said external shoulder defining an annular race; means for indicating the orientation of said piston and said notch radially with respect to said outer tubular member; means for securing said piston in oriented position against radial movement; a second outlet passage from said passageway defined by said orifices and said annular recess;

sealing means carried by said piston sealing said second outlet passage when the piston is in its upper position and opening said second outlet passage when the piston is moved to its lower position; spring biasing means between the bottom of said piston and said bore biasing said piston upwardly against the inlet pressure of drilling fluid in said passageway; and a ball in said race holding said piston in its upper position when the ball is not in said notch; whereby, when said ball is in said notch the piston will move to its lower position to open said second outlet passage to thereby increase said outlet area from said passageway resulting in a noticeable decrease in drilling fluid pressure in said passageway to indicate that the ball is in said notch.

References Cited in the file of this patent UNITED STATES PATENTS 2,109,853 Straatman Mar. 1, 1938 2,142,559 Duus Ian. 3, 1939 2,155,552 Jones Apr. 25, 1939 2,333,691 Smith NOV. 9, 1943 2,600,125 Natl'and et a1 June 10, 1952 2,953,350 Moore Sept. 20, 1960 2,978,032 Hanna Apr. 4, 1961 

1. AN ORIENTING SUB FOR INSERTION IN A DRILL STRING FOR EARTH BORING OPERATIONS COMPRISING: AN OUTER TUBULAR MEMBER HAVING A BORE THERETHROUGH; A TUBULAR PISTON IN SAID BORE AXIALLY AND RADIALLY MOVABLE THEREIN AND HAVING AT LEAST ONE ORIFICE IN ITS WALL NEAR ITS LOWER END, AN EXTERNAL ANNULAR SHOULDER HAVING A DOWNWARDLY FACING NOTCH THEREIN, AND A RESTRICTED OPENING AT ITS LOWER END DEFINING A FIRST OUTLET PASSAGE CONSTITUTING AN OUTLET AREA FOR THE PASSAGE OF DRILLING FLUID FROM SAID SUB; THE HOLLOW OF SAID PISTON FORMING A PASSAGEWAY FOR DRILLING FLUID THROUGH SAID SUB; A TUBULAR SEAL BETWEEN SAID PISTON AND SAID BORE LOCATED BELOW SAID EXTERNAL SHOULDER AND HAVING AN INTERNALLY RECESSED PORTION AT ITS LOWER END TO FORM AN ANNULAR RECESS BETWEEN ITS LOWER INTERNAL SURFACE AND SAID PISTON, THE UPPER END OF SAID SEAL AND THE LOWER SURFACE OF SAID EXTERNAL SHOULDER DEFINING AN ANNULAR RACE; MEANS FOR INDICATING THE ORIENTATION OF SAID PISTON AND SAID NOTCH RADIALLY WITH RESPECT TO SAID OUTER TUBULAR MEMBER; MEANS FOR SECURING SAID POSTON IN ORIENTED POSITION AGAINST RADIAL MOVEMENT; MEANS FOR EQUALIZING PRESSURE BETWEEN SAID RACE AND THE HYDROSTATIC HEAD OF THE WELL BORE; A SECOND OUTLET PASSAGE FROM SAID PASSAGEWAY DEFINED BY SAID ORIFICES AND SAID ANNULAR RECESS; SEALING MEANS CARRIED BY 